The Orc Sergeants were still some distance away from Warthorn who was wearing the Barbaric Helm. So, their battle prowess was yet to be suppressed by it.
'Swoosh'
However, as soon as the Orc Soldier finished his words, Warthorn moved towards them while hammering the Orc Soldiers to death.
Once the Orc Sergeants were within the range of the Barbaric Helm, their battle prowess was suppressed just like the Orc Soldiers.
"Wait…my battle prowess…it seemed to decrease a little."
"The damn old book is also suppressing my battle prowess."
.
.
Soon, the five Orc Sergeants believed the runaway Orc Soldier's earlier story as they looked at the human wearing Goblin Mask and the old book with a serious look on their faces.
"Even though our battle prowess was being suppressed by that Old Book, it is very minimal."